December 20, 2019
Summary: Winds are still blowing over the valley portion of Kern County out of the east or southeast, but only in some areas so far. Here are a few peak wind gusts as of 1:00pm: Tehachapi Hwy east of Bakersfield 20 MPH, Lamont 20MPH, Ranch Road 24 MPH, Mettler 23 MPH, the Grapevine CalTrans station 44 MPH, and the CHP office 47 MPH.
Pressure differences will continue to increase tonight. the largest difference in pressure appears to be between 4 and 8 am Sunday morning. I still feel wind gusts in excess of 50 to 60 MPH are possible near the bottom of the Grapevine and in excess of 35 MPH as far north as Bakersfield with 30 to 40 MPH winds later tonight and Sunday morning along the west side of Kings and Fresno Counties. The front will move through the valley probably between noon and 3:00pm, so I would anticipate winds to die off quickly as pressures equalize.
Several locations in Kern County are already near the 70 degree mark with widespread mid 60s elsewhere as a combination of downslope heating and a southwest flow aloft do their part to contribute to a first balmy day of winter.
Precipitation will begin Sunday with precipitation chances picking up by late morning with rain at times Sunday afternoon through Monday night. this first low pressure system will move through to our south early Tuesday morning, so it’s possible showers will continue for much of Christmas eve day then possibly end as Santa spreads his joy Christmas Eve night. models show the next low will slide southward just off shore, causing bands of showers to pinwheel into the valley Christmas Day, especially during the afternoon and lasting well into Thursday. The origins of this storm are in the far northeast Pacific so expect low snow levels, down into the higher foothills. Showers will taper off Thursday night with only lingering showers mainly over the mountains Friday morning. by then, the main body of low pressure will have moved into the Desert Southwest.
High pressure aloft over the eastern Pacific will shift into California this coming weekend which models continue to indicate will maintain dry conditions through the end of the year. It also appears a strong surface high will develop this coming weekend over the Great Basin for a rather robust off shore flow. Typically, this means extensive fog and low clouds on the valley floor with mostly clear skies elsewhere.
Forecast: Overcast tonight. periods of rain beginning later Sunday morning and continuing through Monday night. showers likely Tuesday morning with a slight chance of showers Tuesday afternoon. Partly to mostly cloudy Christmas Eve night. showers again later Christmas afternoon and at times through Thursday. A chance of showers Thursday night. partly to mostly cloudy Friday. Partly cloudy Friday night and Saturday morning with areas of fog and low clouds possible. Mostly clear Saturday afternoon.
Short Term:
| Madera 50/64/48/52 | Reedley 50/65/49/53 | Dinuba 49/65/48/52 | |
| Porterville 50/65/48/53 | Lindsay 48/65/47/52 | Delano 50/66/49/53 | |
| Bakersfield 54/66/50/52 | Taft 54/64/49/51 | Arvin 51/63/48/53 | |
| Lamont 53/65/49/52 | Pixley 50/65/47/51 | Tulare 48/64/47/51 | |
| Woodlake 49/64/48/52 | Hanford 50/65/49/51 | Orosi 48/65/47/51 | |
Winds: Pressure gradients, or differences, between the interior west and off shore will continue to increase tonight and for a time Sunday morning. it appears the time of strongest winds in Kern County will be between 4 and 8 am Sunday. Winds in excess of 50 to 60 MPH cannot be ruled out at the usual trouble spots like at the bottom of the Grapevine and locally elsewhere at the base of the Tehachapi Mountains. Gusty winds in excess of 35 MPH are certainly possible as far north as Bakersfield. Winds of 30 to 40 in gusts are possible in western Kings and Fresno Counties during this same time frame. Generally east of highway 99 in Tulare and eastern Fresno Counties will be out of the east to southeast at 10 to 20 MPH with local gusts to 25. Winds in Madera County will be out of the southeast, possibly gusting to near 35 MPH.
Winds in all areas will die off by around midday Sunday and will generally be in the 8 to 15 MPH range Sunday afternoon through Christmas Eve night with stronger gusts, especially in the vicinity of showers.
Rain: The chance for rain will begin to increase from west to east by late Sunday morning with periods of rain Sunday afternoon well into Christmas Eve day. During the first phase of this event, the west side and Kern County will be under a strong rain shadow, however once we get into late Sunday night and Monday, we may see a period of more significant precipitation, especially south of Fresno County all the way through roughly the first half of the day Tuesday. We’ll then see a brief dry period Christmas Eve night into early Wednesday. I’m going to up the ante a bit as far as amounts are concerned with possibly .33 or so over the valley portion of Kern County from midday Sunday through Tuesday night. In Madera, Fresno, and Tulare Counties, between .33 and .50 seems plausible with possibly .25 to .33 in Kings and western Fresno Counties.
The only timeframe where the chance of rain is really low will be Christmas Eve night with the chance of showers increasing again Christmas afternoon and showers at times Christmas night through Thursday. There will be a continuing risk of showers for a time through Thursday night. by Friday morning, most if not all the precipitation will be confined to the mountain areas.
Beginning Friday, we should see dry weather up through roughly the first couple of days of 2020.
Frost Discussion: All locations will be well above 32 degrees tonight with above freezing conditions anticipated through at least Thursday morning due to a very active weather pattern. Lower 30s may be possible Friday morning if skies become relatively clear, which currently appears doubtful. However, from this coming Saturday morning and for several days thereafter, upper 20s to lower 30s cannot be ruled out as a north/northwest flow develops behind the Christmas week storms. The pattern setting up over the weekend will be favorable for widespread fog and low clouds. If this comes to pass, would generally keep most locations in the 30s to the lower 40s.
Next report: Sunday morning/December 22